One of the dilemmas for crossword writers and publishers is how to indicate to solvers the length and format of answers. As with all things, there are written and unwritten “rules” but the essential thing is that both parties (setters, solvers) understand each other and there is consistency from crossword to crossword. It’s very common for small, daily, non-cryptic crosswords to contain no word format information at the end of any clue UNLESS the answer is multi-word or hyphenated. Solvers need to simply look at the crossword to work out what’s needed for the rest. Some crosswords tell you that there are multiple words involved but not their lengths (The Listener Crossword), others, like US crosswords, don’t even tell you if more than one word is needed (this very fact allowed the famous CLINTON/BOB DOLE NYT crossword to work).
Even when the word format is supplied, there are potential issues with how different parts of language are indicated. For example, is ADAM’S APPLE (4’1, 5) or (5,5) and should I’LL SAY be indicated any differently since I’LL is a contraction of I WILL? What’s the right thing to do when a term like CLOTHES HORSE appears in different references as CLOTHESHORSE and CLOTHES-HORSE as well? And what about acronyms and abbreviated terms that have entered language as colloquialisms? Take SMSs from The Stickler Weekly 194, for example. I agonised over how to enumerate this answer, as for a non-cryptic I would use (1,1,2) indicating how the answer is spoken: S-M-Ss, but thought this wouldn’t be necessary for a cryptic (turned out that people were more interested in how to pluralise this term that how it was enumerated).
So what’s the answer to these vexing questions? There are no right answers only conventions that have come from years of use, and these conventions may actually vary from publication to publication, but should never vary within a publication. It’s safe to say that almost every major publication ignores any apostrophe in defining the enumeration of answers. The reasoning is simple: apostrophes aren’t entered into the grid no matter their purpose. A possessive apostrophe is ignored just as a substitution for missing letters apostrophe is ignored. Even Italian titles like L’ELISIR D’AMORE are enumerated without the apostrophe to be consistent with English terms. Every now and then there will be calls for the apostrophe to be included, but this hasn’t ever been an established convention. The key in all things to do with crosswords is consistency – a solver will only ever make a mistake in this area once as long as every answer with an apostrophe is handled the same way.
As for the same answer appearing in multiple references in different word formats, again, commonsense needs to be applied. When I write cryptics for the Australian Financial Review, I default to Australia’s national dictionary, The Macquarie Dictionary, when there are discrepancies with other references. However, when I’m writing The Stickler Weekly, that I market as an international crossword, I go with the most popular format, and if they are all different, I stick with Chambers. In this case I’d probably add an entry to the Overseas Help section on the website as well. There’s another “trick” in this area: the biggest complaint is usually that an answer should be two words, even though dictionaries have it a one word, so when in doubt I use the multi-word enumeration as almost no-one will question it since it sounds and look right.